EP3656527B1 - Manufacturing method and deformable construction plate for the mould-free production of a fibre-reinforced moulded part, especially a boat hull - Google Patents

Description

The present invention relates to a manufacturing method and a deformable construction panel for the shapeless manufacture of a fiber-reinforced three-dimensional molded part with an at least partially curved surface, for example for the shapeless manufacture of a fiber-reinforced boat hull, rotor blade or facade element.

Molded parts with at least partially curved surface, in particular boat hulls, made of fiber-reinforced plastic are produced in different ways. The starting point for production is usually a full-surface negative mold in which the molded part to be produced is built up. In this case, the negative mold provides a closed surface that gives the shape, which reproduces a complete negative of the surface profile of the molded part to be produced.

As far as the production of boat hulls is concerned, mats made of glass fiber or carbon fiber fabric are typically inserted into the mold after applying a release agent and possibly a gel coat to the forming closed surface of the negative mold and connected to one another with polyester or liquid epoxy resin. A less expensive method is to spray fiberglass sections mixed with liquid polyester or epoxy onto the gelcoat. According to another, about from U.S. 4,032,689 Known methods are deformable panels made of fiber-reinforced material, such as thin sheets of carbon or glass fiber, between which a foam layer is arranged, inserted into the negative mold. In order to make such panels three-dimensionally deformable, the foam layer is made up of rod-shaped or cube-shaped foam bodies, sections of which are connected to one another via a layer of paper. The paper layer allows the inherently rigid foam bodies to be bent relative to one another. Under and over the through The glass fiber reinforced mats, which are impregnated with a matrix such as epoxy resin or polyester, are arranged on foam bodies held together by paper. After the bodies connected in this way have been inserted into the negative mold, the impregnated mats can harden to form a rigid molded part. This construction method can be used successfully when a negative mold is available and a large number of boat hulls can be produced in it. However, the costs for the production of a negative mold are not affordable for individual buildings.

Another example from WO 2002/095154 A1 known method is also based on the use of a foam element which is provided with slits in order to be able to deform the element three-dimensionally. The cavities formed by the slits are filled with liquid epoxy resin or polyester after they have been placed in a negative mold. A similar procedure is also out DE 691 29 972 T2 known.

EP 487 945 A2 describes elements having a porous layer on which is disposed a slotted substrate. To fix curved shapes, putty is introduced into the widened slots. WO 02/095154 A1 describes elements which have plate segments separated by slits on both sides of a layer of flexible knitted fabric. Here too, after the elements have been bent as desired, hardenable material is introduced into the slots.

Another manufacturing process for boat hulls consists in applying narrow, flexible strips, such as strips made of light cedar wood, to a so-called Mallen framework - i.e. a large number of shaping templates spaced apart in the direction of the keel of the boat hull to be produced - and then covering the outside with a glass fiber mat will. The slats remain connected to the fibre-reinforced layer and can be covered internally by another fibre-reinforced layer, so that the slats act as spacers between two rigid plastic layers. The hulls made by this method are relatively inexpensive. However, such hulls are often too heavy for light boats, which are increasingly in demand today.

US 2005/0006823 A1 describes the production of a multi-layer product on parallel, spaced-apart stencils, with a first and at least a second individual layer being applied one after the other. Curable material is introduced between the layers by means of a vacuum applied between the layers.

The object of the present invention is therefore to create a method with which highly stressable three-dimensional molded parts, for example boat hulls, rotor blades or facade elements, can be produced inexpensively without having to provide an expensive negative mold for this purpose. Another object of the invention is to provide a construction panel whose Surface can preferably form directly the outer skin of a three-dimensionally shaped highly stressable molded part that can be produced therefrom, in particular a boat hull, rotor blade or facade element.

This object is achieved by a method according to independent claim 1 and by a deformable construction board according to independent claim 13. Advantageous configurations of the invention are the subject matter of the dependent claims.

• Bereitstellen eines Laminats, das wenigstens eine Schaumstoffschicht und eine erste faserverstärkte und fluiddichte Trägerschicht aufweist, wobei die erste Trägerschicht mit einer ersten Seite der Schaumstoffschicht verbunden ist;
• Verformbarmachen des Laminats durch einseitiges, vorzugsweise computergesteuertes Einbringen eines oder mehrerer nutenförmiger Schlitze in das Laminat gemäss einem vorbestimmten Schlitzmuster, wobei der eine oder die mehreren Schlitze die Schaumstoffschicht vollständig oder nur teilweise durchdringen, aber nicht in die erste Trägerschicht eindringen;
• Bereitstellen eines Schablonengerüsts, insbesondere eines negativen Mallengerüsts, mit mehreren Stegschablonen, die entlang einer ersten Richtung ausgerichtet und voneinander beabstandet an einer jeweiligen Längsposition entlang einer zur ersten Richtung senkrecht verlaufenden zweiten Richtung angeordneten sind, wobei jede Stegschablone eine formgebende Kontur aufweist, die zumindest bereichsweise einem Querschnittsprofil des herzustellenden Formteils entlang der ersten Richtung an der jeweiligen Längsposition entspricht, so dass die Konturen der Steg-Schablonen in ihrer Abfolge im Schablonengerüst einen Oberflächenverlauf des herzustellenden Formteils nachbilden;
• Einlegen des verformbar gemachten Laminats in das Schablonengerüst, wobei die erste Trägerschicht mit ihrer Ausseiten mit den formgebenden Konturen der Stegschablonen in Kontakt gelangt, so dass das Laminat auf der Aussenseite der ersten Trägerschicht den vom Schablonengerüst definierten Oberflächenverlauf des herzustellenden Formteils einnimmt;
• Vergießen der nach Einlegen in das Schablonengerüst in den Schlitzen verbleibenden Freiräume mit Reaktionsharz im Infusions-Verfahren, insbesondere im Vakuum-Infusions-Verfahren, oder Aufbringen eines mit Reaktionsharz vorimprägnierten Faser-Matrix-Haibzeuges auf die der ersten Trägerschicht gegenüberliegende Seite des Laminats, oder Aufbringen eines Fasergewebe-Reaktionsharz-Handlaminats auf die der ersten Trägerschicht gegenüberliegende Seite des Laminats;
• Aushärten-Lassen des Reaktionsharzes;
• Entnehmen des so erhaltenen Formteils aus dem Schablonengerüst nach dem Aushärten des Reaktionsharzes.

According to the invention, a manufacturing method is provided for the free-form manufacture of a fiber-reinforced three-dimensional molded part with an at least partially curved surface, for example a fiber-reinforced boat hull, rotor blade or facade element, which comprises the following steps:

• providing a laminate having at least one foam layer and a first fiber-reinforced and fluid-tight backing layer, the first backing layer being bonded to a first side of the foam layer;
• Making the laminate deformable by one-sided, preferably computer-controlled, introduction of one or more groove-shaped slits into the laminate according to a predetermined slit pattern, the one or more slits penetrating the foam layer completely or only partially, but not penetrating into the first carrier layer;
• Providing a template framework, in particular a negative Mallen framework, with a plurality of bar templates, which are aligned along a first direction and spaced apart from one another and are arranged in a respective longitudinal position along a second direction running perpendicular to the first direction, each bar template having a shaping contour which, at least in regions, has a Corresponds to the cross-sectional profile of the molded part to be produced along the first direction at the respective longitudinal position, so that the contours of the web templates in their sequence in the template framework simulate a surface profile of the molded part to be produced;
• Insertion of the laminate that has been made deformable into the stencil framework, with the outside of the first carrier layer coming into contact with the shaping contours of the web stencils, so that the laminate on the outside of the first carrier layer assumes the surface profile of the molded part to be produced, which is defined by the stencil framework;
• Casting the free spaces remaining in the slots after insertion into the template frame with reaction resin using the infusion method, in particular the vacuum infusion method, or applying a fiber matrix semi-finished product pre-impregnated with reaction resin to the side of the laminate opposite the first carrier layer, or applying a fiber fabric-reaction resin hand laminate on the side of the laminate opposite the first carrier layer;
• allowing the reaction resin to harden;
• Removal of the molded part thus obtained from the template frame after the reaction resin has hardened.

The method according to the invention is distinguished on the one hand by the use of a template framework, in particular a negative mold framework, which comprises a plurality of bar templates or molds. In contrast to full-surface negative molds, such templates or mold frames can be produced very inexpensively, for example from inexpensive chipboard. Nevertheless, like full-surface negative forms, they allow multiple uses. In addition, the template framework can advantageously be temporarily dismantled until it is used again, and it requires little storage space. In particular, the use of a template framework enables the molded part to be produced "free of mold".

On the other hand, the method is characterized by the use of the laminate according to the invention and by making it deformable by introducing slits, for example groove-shaped slits, on one side. The groove-shaped slits, which penetrate the foam layer completely or only partially, make it possible in a simple manner to deform the laminate in a concave manner, viewed from the slit side. This allows the slotted laminate easily inserted into the stencil frame, the laminate on the outside of the first carrier layer automatically taking on the, in particular three-dimensional, surface profile of the molded part to be produced, which is defined by the stencil frame.

The slots are made in the laminate on one side from the side of the laminate opposite the first carrier layer.

In particular, it is made possible that the first carrier layer can advantageously already form a finished surface of the molded part to be produced, since the slits do not penetrate into the first carrier layer. For this purpose, the side of the first carrier layer opposite the foam layer preferably has an essentially smooth surface. In addition, the non-slotted first carrier layer makes it easier to seal the laminate for the vacuum infusion process, in that the first carrier layer forms part of the seal for the free spaces remaining in the slots after insertion into the template framework. The first carrier layer is therefore designed to be fluid-tight, in particular gas-tight.

In addition, there is no time pressure when inserting the pre-processed laminate, since the laminate to be inserted is not impregnated with a filling matrix. This is because no hardenable or already hardening filler is present in the laminate until the casting or application of the pre-impregnated semi-finished fiber matrix product or the hand laminate.

The laminate preferably forms the finished molded part after the reaction resin has hardened and been removed from the template frame.

The pre-impregnated fibre-matrix semi-finished product is characterized by good processability and ensures a uniform and high quality of the molded part to be produced. Such pre-impregnated fiber matrix semi-finished products are also known as prepreg (short for pre-impregnated fibres). Before curing, the matrix is in the partially cross-linked, so-called B-state and is pasty to solid, but can be liquefied again by heating. The fibers contained can be present as a purely unidirectional layer, as a woven fabric or scrim. Prepreg is usually available in web form, wound on rolls. Further advantages of such fiber matrix semi-finished products are their low undulation and the high proportion of fiber volume.

Provision can be made for the laminate to consist exclusively of the first carrier layer and the foam layer arranged thereon. The laminate according to the invention is therefore preferably a two-layer laminate. The molded part to be produced can therefore be made exclusively from such a two-layer laminate cast with reaction resin, in particular when the remaining free spaces between the slits are cast in the (vacuum) infusion process. As a result, additional work steps and/or components can advantageously be omitted for the production of the molded part. Alternatively, instead of casting with reaction resin, a hand laminate or a pre-impregnated fiber matrix semi-finished product can be applied to the slotted side of the foam layer

According to an advantageous embodiment of the invention, however, it can also be provided that the laminate has a second fiber-reinforced carrier layer, which is connected to a second side of the foam layer opposite the first side. In this configuration, the laminate forms a sandwich laminate. In particular, it can be provided that the laminate consists exclusively of the first and second carrier layer and the foam layer arranged between them. The laminate according to the invention is therefore preferably a three-layer laminate. The molded part to be produced can be made exclusively from the three-layer laminate, with a hand laminate or a pre-impregnated fiber matrix semi-finished product additionally being applied to the second carrier layer, or the free spaces remaining in the slits being cast with curing reaction resin using the (vacuum) infusion method will. As a result, additional work steps and/or components can also advantageously be omitted for the production of the molded part.

If a second carrier layer is present, the one or more groove-shaped slits are made in the laminate according to the predetermined slit pattern in such a way that the groove-shaped slits completely penetrate the second carrier layer in order to make the laminate deformable.

The fiber reinforcement of the first and second carrier layer advantageously guarantees sufficient dimensional stability and pressure resistance of the molded part to be produced. Provision is preferably made for the first and/or second fiber-reinforced carrier layer to have a fiber-reinforced, in particular flexible, plastic plate. The first and/or second fiber-reinforced carrier layer can in particular be carbon fiber and/or glass fiber reinforced.

Like the first carrier layer, the second carrier layer can also preferably be designed to be fluid-tight, in particular gas-tight.

According to a further advantageous embodiment of the invention, it can be provided that the reaction resin is allowed to harden under vacuum. A fluid-tight film is preferably applied to the side of the laminate opposite the first carrier layer, in particular - if present - to the second carrier layer, or to the pre-impregnated fiber matrix semi-finished product or to the hand laminate, and opposite the entire laminate to the free edges of the entire laminate, i.e. on the free edges of the laminate, the fiber matrix semi-finished product or the hand laminate.

The fluid-tight film used for sealing can remain connected to the laminate structure as part of the molded part to be produced. Alternatively, the fluid-tight film can be detached from the laminate after curing—either before or after the cured laminate/molding is removed from the template frame. In this case, the fluid-tight film preferably has a release agent on its second carrier layer, the hand laminate or the Fiber matrix semi-finished surface facing to facilitate the release after curing.

According to an advantageous embodiment of the invention, it can be provided that the laminate is provided in the form of several separate construction panels with a corresponding laminate structure, made deformable and inserted into the template frame, the several construction panels being arranged next to one another when they are inserted into the template frame and then - preferably flush - connected to each other, in particular glued or welded. This considerably simplifies the production of very large parts, such as boat hulls, rotor blades or facade elements.

The edges of the individual construction panels are preferably cut to size before or after being made preformable in such a way that adjacent construction panels abut without a gap after being placed in the template frame, at least in the region of the first carrier layer. In particular, the edges of the individual construction panels can be cut to an arc shape, at least in certain areas. The cutting of the edges is preferably computer-controlled. The cutting of the edges can particularly preferably be based on a CAD model of the molded part to be produced.

Depending on the size of the molded part to be produced, the individual construction panels can be up to several meters long and wide. The respective size and/or shape of the construction panels after cutting to size and/or the spacing of the web templates along the second direction is preferably selected in such a way that each of the several construction panels, after being placed in the template frame, at the position predetermined for it, over the outside of the first Carrier layer with the shaping contour of several, ie at least two web templates come into contact. As a result, each construction panel on the unslit outside of the first carrier layer is forced to assume the shape of the surface of the molded part to be produced, which is defined by the template frame.

The construction panels are preferably made deformable by introducing one or more groove-shaped slits before they are inserted and/or assembled (joined). In principle, however, it is also conceivable for at least part of the slot to be made after insertion.

According to a further advantageous embodiment of the invention, the slit pattern can have a honeycomb pattern. A honeycomb pattern advantageously allows the laminate or the construction panels to be deformed in a particularly flexible manner.

However, it is also conceivable for the slot pattern to have a stripe pattern, a diamond pattern, a rectangular pattern, a square pattern, a triangular pattern, an octagon pattern, a polyhedron pattern or a pattern made up of a number of circular or oval slots. The stripe pattern can have, for example, a plurality of slits, which in particular run parallel to one another. Such a pattern is fundamentally useful when the laminate or the construction panel is to be deformed according to the surface profile of the molded part to be produced, which essentially corresponds to a curvature in only one direction, namely perpendicular to the longitudinal extension of the stripe pattern. On the other hand, rectangular, square, triangular, octagonal, polyhedron or honeycomb patterns are particularly suitable when the laminate or the construction board is deformed or curved in two directions, in particular in two directions transverse to one another, in accordance with the shape of the surface of the molded part to be produced or perpendicular directions.

It is also conceivable that the slit pattern has any combination of the aforementioned patterns. For example, the laminate or one or more of the structural panels can have at least a first region with a first slit pattern and at least a second region with a second slit pattern, the first slit pattern being different from the second slit pattern. For example, the first slot pattern in the first area can be a stripe pattern made up of several, in particular parallel to one another having running slits in order to allow deformation in only one direction perpendicular to the longitudinal extent of the stripe pattern in the first region. In contrast, the second slit pattern in the second area can have a rectangular, square or honeycomb pattern, for example, in order to enable deformation or curvature in two directions, in particular in two directions running transversely or perpendicularly to one another, in the second area.

According to a further advantageous embodiment of the invention, it can be provided that the slot pattern depends on a curvature of the molded part to be produced, i.e. depending on the radius of the deformation, areas with different local slot depths, with different local slot widths, with different local slot profiles and/or with different local slot density. In this way, areas of different deformability can be generated in a targeted manner.

In particular, it can be provided that the slit pattern, preferably computer-based, is determined in such a way that a local slit density, a local slit shape, a local slit width and/or a local slit depth in those areas of the laminate that have a higher deformability corresponding to a more curved surface profile of the molded part to be produced is greater than the local slit density, local slit shape, local slit width and/or local slit depth in other areas of the laminate that require lower deformability corresponding to a less curved surface profile of the molded part to be produced. In this way, it can be achieved in an advantageous manner that, by suitably selecting the slot width, slot shape, slot depth and slot density, just as much slot volume is generated as is necessary for the local deformability required in each case. On the one hand, this reduces the technical effort involved in introducing the groove-shaped slots. On the other hand, the free spaces remaining in the slits after insertion into the stencil framework and possibly having to be cast with reaction resin can be minimized in this way. This advantageously reduces the amount of reaction resin to be introduced and thus also the total mass of the molded part to be produced.

With regard to a honeycomb pattern, it is possible, in particular, to also dimension the honeycomb smaller in areas in which the bending radius must be small, so that the structural panels can be deformed correspondingly more easily. In areas where only a small deformation is necessary, the individual honeycombs can be dimensioned correspondingly larger and/or their distances, i.e. slot widths, can be selected correspondingly smaller.

In order to further reduce the amount of reaction resin that may have to be introduced in the infusion process and thus the total mass of the molded part to be produced, the slit pattern, in particular the local slit profile, the local slit density, the local slit width and/or the local slit depth, according to a further advantageous embodiment of the invention , preferably computer-based, are determined in such a way that the volume of the free spaces in the laminate defined by the slits increases by deforming by at least 50%, in particular by at least 75%, preferably by at least 80%, particularly preferably by at least 90%, after insertion into the template framework % reduced. In particular, the slit pattern can be determined, preferably computer-based, in such a way that opposite flanks of the groove-shaped slits touch each other almost or at least in certain areas after they have been placed in the template framework.

According to a further advantageous embodiment of the invention, it can be provided that at least some of the slots have a V-shaped or U-shaped or trapezoidal or rectangular slot profile or a slot profile with two slot walls parallel to one another, at least before they are placed in the stencil framework. Such profile shapes can be introduced into the laminate or the construction panels in a technically particularly simple manner. As already described above, the slit pattern can be designed to have areas with different local slit profiles, such as an area with a V-shaped slit profile and another area with a rectangular slit profile or a slit profile with two mutually parallel slit walls. According to a further advantageous embodiment of the invention, the foam layer has a closed-pore foam or consists of a closed-pore foam. This prevents reaction resin from penetrating the interior of the foam. This also advantageously reduces the amount of reaction resin that may need to be introduced, and thus the total mass of the molded part to be produced. The foam layer preferably has a rigid foam, in particular a closed-pore rigid foam, or consists of a rigid foam, in particular a closed-pore rigid foam. In this way, sufficient dimensional stability of the molded part to be produced can be ensured.

The reaction resin is preferably an epoxy resin, vinyl ester resin or polyester resin, in particular an unsaturated polyester resin. These substances are characterized by easy processing and a long service life. In addition, these substances are particularly suitable for vacuum infusion.

According to one of the alternatives of the present invention, the free spaces remaining in the slots after insertion can be cast with curing reaction resin in the vacuum infusion process and the reaction resin can then be allowed to cure under vacuum. In the same way, the curing of the reaction resin can take place under vacuum when using a pre-impregnated fiber matrix semi-finished product or a fiber fabric-reaction resin hand laminate according to the other two alternatives of the present invention. For this purpose, the laminate placed in the template frame or the construction panels placed in the template frame and connected to one another are evacuated under a foil. The film is placed on the side opposite the first carrier layer, i.e. for example on the second carrier layer, on the pre-impregnated fiber matrix semi-finished product or the fiber fabric-reaction resin hand laminate and sealed at the edges of the overall construction. A vacuum source, such as a vacuum pump, is connected to the sealed overall construct at one or more points.

For the vacuum infusion process, the sealed laminate or structural panels bonded together and sealed are also fluidly connected to a reactive resin reservoir at one or more other locations, preferably opposite the one or more vacuum source ports. By creating the vacuum, the reaction resin is thus sucked into the free spaces remaining in the slots after insertion (impregnation).

The slit pattern is preferably selected in such a way that several, in particular all, slits of the slit pattern are in fluid communication with one another. This significantly simplifies the vacuum infusion process, since the number of connection points for the vacuum source can be kept low.

After the remaining free spaces have been completely cast or the pre-impregnated fiber matrix semi-finished product has been applied or the fiber fabric-reaction resin hand laminate has been applied, the reaction resin is cured. Curing can preferably take place at room temperature and last for several hours, around 12 or 24 hours.

A further aspect of the present invention relates to a deformable construction panel for the shapeless production of a fiber-reinforced three-dimensional molded part, in particular a fiber-reinforced boat hull, rotor blade or facade element. The construction panel has a laminate structure which has at least one foam layer and a first fiber-reinforced and fluid-tight carrier layer. The first backing layer is bonded to a first side of the foam layer. Furthermore, the construction board has one or more slits on one side, which form a slit pattern, the one or more slits penetrating the foam layer completely or only partially, but not penetrating into the first carrier layer.

The construction panel according to the invention is particularly suitable for carrying out the manufacturing method described herein for the mold-free manufacture of a fiber-reinforced three-dimensional molded part with at least in some areas curved surface, in particular a fiber-reinforced boat hull, rotor blade or facade element.

The construction board can consist exclusively of the first fiber-reinforced carrier layer and the foam layer arranged on top.

According to an advantageous embodiment, the construction panel or the laminate structure can have a second fiber-reinforced carrier layer, which is connected to a second side of the foam layer opposite the first side. This structure corresponds to a sandwich laminate or sandwich laminate structure. In this configuration, the groove-shaped slots completely penetrate the second carrier layer.

The construction board according to the invention is preferably a three-layer construction board, which consists exclusively of the first and second fiber-reinforced carrier layer and the foam layer arranged in between as the core layer.

As already described in connection with the manufacturing method according to the invention, the slit pattern preferably has a honeycomb pattern. A honeycomb pattern advantageously allows the laminate or the construction panels to be deformed in a particularly flexible manner. However, it is also conceivable for the slot pattern to have a stripe pattern, a diamond pattern, a rectangular pattern, a square pattern, a triangular pattern, an octagon pattern, a polyhedron pattern or a pattern made up of a number of circular or oval slots. It is also conceivable that the slit pattern has any combination of the aforementioned patterns.

As also already described in connection with the manufacturing method according to the invention, it can be provided that the slit pattern has areas with different local slit depths, with different local slit widths, with different local slit profiles and/or with different local slit densities.

According to a further advantageous embodiment of the invention, at least some of the slots can have a V-shaped or U-shaped or trapezoidal or rectangular slot profile or a slot profile with two slot walls parallel to one another.

The foam layer preferably has a closed-cell foam or consists of a closed-cell foam. As a result, the total mass of the molded part to be produced from the construction board can be kept low, in particular if the free spaces created between the slots are optionally filled with reaction resin. Because of the closed porosity, later reaction resin cannot penetrate into the interior of the foam. The foam layer preferably has a rigid foam, in particular a closed-pore rigid foam, or consists of a rigid foam, in particular a closed-pore rigid foam. In this way, sufficient dimensional stability of the molded part to be produced can be ensured.

According to a further advantageous embodiment of the invention, the first and/or second fiber-reinforced carrier layer can comprise a fiber-reinforced flexible plastic plate. The first and/or second fiber-reinforced carrier layer can in particular be carbon fiber and/or glass fiber reinforced.

Further goals, advantages, features and application possibilities of the present invention result from the following description of exemplary embodiments according to the drawings. All the features described and/or illustrated form the subject matter of the present invention, either alone or in any meaningful combination, even independently of their summary in the claims or their back-reference.

Fig. 1

ein erstes Ausführungsbeispiel einer erfindungsgemässen Konstruktionsplatte zum formlosen Herstellen eines faserverstärkten Formteils;

Fig. 2

ein Detailausschnitt der Konstruktionsplatte gemäss Fig. 1 vor dem Verformen;

Fig. 3

ein Detailausschnitt der Konstruktionsplatte gemäss Fig. 1 nach dem Verformen;

Fig. 4

ein zweites Ausführungsbeispiel einer erfindungsgemässen Konstruktionsplatte zum formlosen Herstellen eines faserverstärkten Formteils;

Fig. 5

ein Ausführungsbeispiel eines Schablonengerüsts zum formfreien Herstellen eines dreidimensional geformten Bauteils, vorliegend beispielsweise eines Bootsrumpfs; und

Fig. 6-9

ein Ausführungsbeispiel eines erfindungsgemässen Verfahrens zum formfreien Herstellen eines Bootsrumpfs.

Show it:

1

a first embodiment of a construction panel according to the invention for the informal production of a fiber-reinforced molded part;

2

a detail of the construction plate according to 1 before deforming;

3

a detail of the construction plate according to 1 after deforming;

4

a second embodiment of a construction board according to the invention for the informal production of a fiber-reinforced molded part;

figure 5

an embodiment of a template framework for the shape-free production of a three-dimensionally shaped component, in this case, for example, a boat hull; and

Figures 6-9

an embodiment of a method according to the invention for the free-form manufacture of a boat hull.

the Figures 1-3 show a first exemplary embodiment of a construction panel 10 according to the invention, which can form the starting point for the shapeless production of a fiber-reinforced molded part 1, such as a boat hull 2 (see Figures 6-9 ). The construction panel 10 has a laminate structure which includes a foam layer 13 , a first fiber-reinforced carrier layer 11 and a second fiber-reinforced carrier layer 12 . Alternatively, it is conceivable that the construction panel 10 only has the first fiber-reinforced carrier layer 11 and the foam layer, but no second carrier layer.

In the present exemplary embodiment, the foam layer 13 consists of a closed-cell rigid foam. The first carrier layer 11 is a flexible glass or carbon fiber reinforced plastic plate with a smooth surface on one side preferably forms the finished outer surface of the molded part to be produced, for example the hull of a boat. The side of the first support layer 11 opposite the smooth surfaces is non-detachably connected to a first side of the closed-cell foam layer 13 . The second carrier layer 12 is also a flexible glass- or carbon-fibre-reinforced plastic plate, which is permanently connected to a second side of the foam layer 13 opposite the first side. The two plastic plates of the first and second carrier layer 11, 12 are consequently held at a distance from one another by the foam layer 13 made of hard foam and initially form a rigid body.

In order to make the construction plate 10 deformable for the production of molded parts with an at least partially curved surface - as in the present case, for example for the production of a boat hull - according to the present invention, several e.g. The slits are made according to a predetermined slit pattern 20, preferably computer-controlled, in particular based on a CAD model of the molded part to be produced, in such a way that the groove-shaped slits 21, 22, 23 penetrate the second carrier layer 12 completely and the foam layer 13 only partially , but not penetrate into the first carrier layer 11 .

In the embodiment according to the Figures 1-3 the slit pattern 20 is a stripe pattern 24 which is formed by the plurality of slits 21, 22, 23 running parallel to one another. How in particular 2 can be seen, the slit profile of the slits 21, 22, 23 is V-shaped, with each slit 21, 22, 23 tapering starting from the second carrier layer 12 in the direction of the foam layer 13. The slots 21 , 22 , 23 formed in this way make it possible to deform the construction panel 10 concavely, viewed from the slotted side, ie on the side of the second support layer 12 . Such a stripe pattern 20 is particularly useful if the construction panel 10 is to be deformed according to the surface profile of the molded part to be produced, which essentially corresponds to a curvature in only one direction, namely perpendicular to the longitudinal extension of the stripe pattern 24 .

As further in the Figures 1-3 is shown, the slit pattern 10 has areas B21, B22, B23 of different local slit densities. In the present exemplary embodiment, the local density of the slits 21 is greatest in the area B21 and gradually decreases over the area B22 with the slits 22 into the area B23, in which the local density of the slits 23 is lowest.

The varying slot density in the areas B21, B22, B23 is selected depending on the curvature of the molded part to be produced, i.e. depending on the radius of the desired deformation. The slit density is greater in those areas that require greater deformability corresponding to a more curved surface profile of the molded part to be produced than in those areas that require lower deformability corresponding to a less curved surface profile of the molded part to be produced. The same can also apply to the slot width and slot depth.

The slit pattern 20, in particular the local slit profile, the local slit density, the local slit width, the local slit shape and/or the local slit depth is preferably determined in such a way that—as in 3 shown - the volume of the voids 28 defined by the slots is reduced by at least 50% after deformation. The slit pattern 20 is preferably selected in such a way that opposite flanks of the groove-shaped slits 21, 22, 23 almost touch or even touch at least in certain areas after the deformation.

4 shows a second exemplary embodiment of the construction board 10 according to the invention. The construction board 10 shown there has the same laminate structure as the construction board 10 according to FIGS Figures 1-3 . Identical or similar features are therefore provided with identical reference symbols. In contrast to the construction plate 10 according to the Figures 1-3 has the slot pattern 20 of the construction panel 10 according to 4 a honeycomb pattern 25 in which hexagonal bodies are formed after making the slits 26 in the second carrier layer 12 and part of the foam layer 13, which are connected to one another via the first carrier layer 11 and the unslit part of the foam layer 13 are connected. The honeycomb pattern 25 allows a particularly flexible deformability of the construction panel 10. The honeycomb pattern 25 is particularly useful if the construction panel 10 or a laminate composed of it is deformed or curved in two directions, in particular in two directions transverse to one another, according to the surface profile of the molded part to be produced running directions should learn.

Based on Figures 5-9 An exemplary embodiment of the method according to the invention for the free-form production of a fiber-reinforced molded part 1 with an at least partially curved surface is explained below using the example of a boat hull 2 to be produced. The starting point of the method is formed by a plurality of construction panels 10, which have the laminate structure explained above and in which, according to the method according to the invention, a slit pattern, such as a stripe pattern 24 as in FIGS Figures 1-3 shown or a honeycomb pattern 25 as in 4 shown is introduced. As explained above, the slit pattern 20, the slit density, slit shape, slit width and/or slit depth are selected locally depending on the curvature of the boat hull to be manufactured in such a way that each of the construction panels 10 at its intended place of use in the boat hull 2 has a has local curvature of the hull 2 to be produced adapted deformability. The respective slot patterns 20, 24, 25 are preferably determined and introduced in a computer-based manner using a CAD model of the boat hull 2 to be manufactured.

According to the invention, the construction panels 10 prepared in this way are then placed in a negative template framework 50, also known as a negative Mallen framework. As in figure 5 , although shown only schematically and in part, the stencil framework 50 comprises a plurality of bar stencils 51, 52, 53, also called Mallen. These are aligned along a first direction, in this case corresponding to the transverse extension of the hull 2 to be produced, and spaced apart from one another at a respective longitudinal position along a second direction, in this case along the longitudinal extension of the hull 2 to be produced, ie perpendicular to the first direction.

Depending on the size of the molded part to be produced, the distance between two adjacent web templates 51, 52, 53 can be a few centimeters to a few meters, for example 30 cm, 40 cm or 50 cm. The distance along the length of the hull 2 to be manufactured can vary depending on the course of the curvature. Each web template 51, 52, 53 has a shaping contour 54, 55, 56, which at least partially corresponds to a cross-sectional profile of the boat hull 2 to be produced along the first direction at the respective longitudinal position, so that the contours 54, 55, 56 of the web Templates 51, 52, 53 in their sequence in the template framework 50 simulate a surface profile of the hull 2 to be produced. The web templates 51, 52, 53 can be easily calculated using a CAD model for any point of the boat hull 2 along its length and can be cut out, for example, CAD-based using a milling machine or saw or a laser cutting device. Such a template framework 50 can be produced very inexpensively from inexpensive chipboard and, if another boat is to be built, requires only little storage space until it is used again. The individual web templates 51, 52, 53 can be made from a rectangular plate which is connected to one another at the bottom and at the two upper ends via slats 58.

The construction panels 10 provided with slots can now be inserted into this template framework 50 (cf. 6 ). The insertion of the pre-processed construction panels 10 is very simple. In particular, there is no time pressure, since no hardenable filler is present in the construction panels 10 in advance. The individual plates 10 with, for example, the striped or honeycomb slot pattern can be up to several meters long and wide, depending on the size of the boat. Since the entire shape or area of the molded part to be produced is known from the existing CAD model, the edges, ie the longitudinal and width edges, of the construction panels 10 can be cut before or after preforming, preferably computer-controlled, in such a way that adjacent construction panels are 10 after insertion into the stencil frame 50 at least in the region of the first carrier layer 11, preferably across all layers 11, 12, 13, without any spacing collide. The edges of the construction panels 10 can in particular be cut in an arc shape. After insertion, each construction panel 10 is supported by a plurality of web templates 51, 52, 53, so that each construction panel 10 necessarily has the planned hull shape on the respective outer surface of the non-slotted carrier layer 11 in accordance with the respective shaping contour 54, 55, 56 of the web templates 51, 52, 53 assumes.

At the joints 19 between the individual construction panels 10, these are preferably flush, glued together. 7 shows the state after inserting and connecting the construction panels 10. Compared to 6 It can be clearly seen that the opposite flanks of the slots 21, 22, 23 almost touch each other after they have been placed in the template framework 50, in particular that the volume of the free spaces 28 defined by the slots 21, 22, 23 has increased after they have been placed in the template framework significantly reduced, at least by 50%.

After the construction panels 10 have been laid in and connected, they form a laminate 5. Alternatively, the laminate 5 can already be present as a one-piece laminate before the slits are laid in and made. However, the laminate 5 is preferably - as described above - provided in the form of several separate construction panels 10 with a corresponding laminate structure, made deformable and inserted into the template framework 50, the several construction panels 10 being arranged next to one another in the template framework 50 and connected to one another, in particular glued or be welded.

After inserting and connecting the construction panels 10 - as in 8 in a cross-sectional view schematically represents - the remaining free spaces in the slots 21, 22, 23 in the present embodiment cast in the vacuum infusion process with a hardening reaction resin. For this purpose, a plastic film 80 is placed on the inside of the boat hull 2 to be produced, ie on the exposed side of the second carrier layer 12, and sealed on the upper free edges 18 in the area of the slats 58, which connect the web templates 51, 52, 53 to one another. The film 80 is in the longitudinal direction of the boat hull 2 to be created on one of the two longitudinal edges, preferably connected to a vacuum pump 60 via a plurality of hoses 61 . On the opposite side, hoses 71 are also guided into the space between the foil 80 and the inner side of the construction panel 10 or of the laminate 5 provided with slits. The other end of the hoses 71 is immersed in a container 70 with liquid reaction resin, such as epoxy resin, vinyl ester resin or unsaturated polyester resin. When the vacuum pump 60 is switched on, the space between the construction panels 10 slotted on one side or the laminate 5 slotted on one side and the film 80 is evacuated the opposite side until liquid plastic has also reached there.

The introduced liquid reaction resin penetrates the slits, but cannot penetrate the material of the foam layer, since this has closed pores. Consequently, only a minimal amount of liquid plastic is required to hold the deformed structural panels 10 or laminate 5 together after curing. The amount of plastic introduced is very small and consequently the fuselage 2 is very light.

As an alternative to the vacuum infusion process, a fiber matrix semi-finished product pre-impregnated with reaction resin or a hand-laminated fiber fabric-reaction resin can be applied to the side of the laminate 5 opposite the first carrier layer 11 and the reaction resin can then be allowed to harden. Curing can also take place under vacuum, as in the vacuum infusion process. A foil - as described for the vacuum infusion method - can also be used.

After the reaction resin has hardened, for example after 12 or 24 hours, the vacuum can be released and the plastic film 80 can be removed from the fuselage 2 that has now been created. The outside of the fuselage is formed by the outside of the first carrier layer 11 and is already substantially complete smooth. The inside also requires little, if any, effort to smooth the surface.

9 shows the finished boat hull 2 in a cross-sectional view after removal from the template framework. Bulkheads can be inserted where necessary in the boat hull 2 produced in this way, preferably before removal from the template framework, in order to keep the boat hull 2 in shape until the deck is put on or later for the attachment of shrouds and the like.

Of course, not only boat hulls, but also any other three-dimensional shapes can be produced in the manner described.

Claims (19)

1. A manufacturing method for the mold-free production of a fiber-reinforced three-dimensional molded part (1) having a surface that is curved at least in regions, in particular a boat's hull (2), rotor blade or façade element, wherein the method comprises

   providing a template framework (50), in particular a negative mold framework, comprising a plurality of partition templates (51, 52, 53) that are oriented in a first direction and are arranged so as to be spaced apart from one another in a relevant longitudinal position in a second direction extending perpendicularly to the first direction, wherein each partition template (51, 52, 53) has a shaping contour (54, 55, 56) which corresponds, at least in regions, to a cross-sectional profile of the molded part (1) to be produced in the first direction in the relevant longitudinal position, such that the contours (54, 55, 56) of the partition templates (51, 52, 53) recreate a surface shape of the molded part (1) to be produced in their sequence in the template framework (50),

   wherein the manufacturing method comprises the following steps:

   - providing a laminate (5) which has at least one foam layer (13) and one first fiber-reinforced and fluid-tight carrier layer (11), wherein the first carrier layer is connected to a first side of the foam layer (13);

   - rendering the laminate (5) deformable by making one or more grooves (21, 22, 23, 26) in the laminate (5) on one side, preferably in a computer-controlled manner, in accordance with a predetermined groove pattern (20), wherein the one or more grooves (21, 22, 23, 26) completely or only partially penetrate the foam layer (13), but do not penetrate the first carrier layer (11);

   - laying the laminate (5), which has been rendered deformable, into the template framework (50), wherein the first carrier layer (11) comes into contact with the shaping contours (54, 55, 56) of the partition templates (51, 52, 53) by its outer faces such that the laminate (5) takes on the surface shape of the molded part (1) to be produced, as defined by the template framework (50), on the outer face of the first carrier layer (11);

   - filling the open spaces (28) remaining in the grooves (21, 22, 23, 26) once said laminate has been laid into the template framework (50) with reaction resin in an infusion process, in particular in a vacuum infusion process, or applying a fiber-matrix semi-finished product pre-impregnated with reaction resin to the side of the laminate (5) opposite the first carrier layer (11), or applying a fibrous-tissue reaction-resin hand lay-up laminate to the side of the laminate (5) opposite the first carrier layer (11);

   - allowing the reaction resin to cure;

   - removing the molded part (1) thus obtained from the template framework (50) after the reaction resin has cured.
2. The method according to Claim 1, characterized in that the laminate has a second fiber-reinforced carrier layer (12) which is connected to a second side of the foam layer (13) opposite the first side, and wherein the one or more grooves (21, 22, 23, 26) are made in the laminate (5) in accordance with the predetermined groove pattern (20) such that the grooves (21, 22, 23, 26) completely penetrate the second carrier layer (12).
3. The method according to Claim 1 or 2, characterized in that the reaction resin is allowed to cure under vacuum, wherein a fluid-tight film (80) is applied to the side of the laminate (5) opposite the first carrier layer (11) or to the pre-impregnated fiber-matrix semi-finished product or to the hand lay-up laminate and is sealed from the laminate (5) at the free edges (18) of the laminate (5) or the fiber-matrix semi-finished product or the hand lay-up laminate.
4. The method according to any of the preceding claims, characterized in that the laminate (5) is provided in the form of a plurality of separate structural panels (10) having a corresponding laminate structure, is rendered deformable, and is laid into the template framework (50), wherein the plurality of structural panels (10) are arranged beside one another when they are laid into the template framework (50) and are interconnected, in particular bonded or welded.
5. The method according to Claim 4, characterized in that the edges of the structural panels (10) are cut to size, before or after said panels are rendered deformable, preferably in a computer-controlled manner, such that adjacent structural panels (10) abut one another without any spacing at least in the region of the first carrier layer (11) after being laid into the template framework (50).
6. The method according to any of the preceding claims, characterized in that the groove pattern (20) has a honeycomb pattern (25).
7. The method according to any of the preceding claims, characterized in that the groove pattern (20) has regions having a different local groove depth, a different local groove width, a different local groove profile, and/or groove shape, and/or a different local groove density, depending on a curvature of the molded part (1) to be produced.
8. The method according to any of the preceding claims, characterized in that the groove pattern (20) is determined, preferably in a computer-based manner, such that a local groove density, groove shape, groove width, and/or groove depth is greater in regions of the laminate (5) requiring greater deformability corresponding to a more heavily curved surface shape of the molded part (1) to be produced than a local groove density, groove shape, groove width, and/or groove depth in regions of the laminate (5) requiring less deformability corresponding to a less curved surface shape of the molded part to be produced.
9. The method according to any of the preceding claims, characterized in that the groove pattern (20), in particular a local groove shape, a local groove density, a local groove width, and/or a local groove depth is determined, preferably in a computer-based manner, such that opposite sides of the channel-shaped grooves (21, 22, 23, 26) are in contact at least in regions after the laminate is laid into the template framework (50) and/or such that the volume of the open spaces (28) in the laminate (5) defined by the grooves (21, 22, 23, 26) is reduced by at least 50% by deformation after the laminate is laid into the template framework (50).
10. The method according to any of the preceding claims, characterized in that at least some of the grooves (21, 22, 23, 26) have a V-shaped, trapezoidal, or rectangular groove profile or a groove profile having two parallel groove walls, at least before the laminate is laid into the template framework (50).
11. The method according to any of the preceding claims, characterized in that the foam layer (13) has a closed-cell foam, a rigid foam, or a closed-cell rigid foam.
12. The method according to any of the preceding claims, characterized in that the first carrier layer (11) and/or the second carrier layer (12) has a fiber-reinforced plastics panel.
13. A deformable structural panel (10) for the mold-free production of a fiber-reinforced three-dimensional molded part (1), in particular a boat's hull (2), rotor blade or façade element, wherein the structural panel (10) has a laminate structure which has at least one foam layer (13) and one first fiber-reinforced carrier layer (11), wherein the first carrier layer is connected to a first side of the foam layer (13) and the structural panel (10) has one or more grooves (21, 22, 23, 26) on one side which form a groove pattern (20), wherein the one or more grooves (21, 22, 23, 26) completely or only partially penetrate the foam layer (13), but do not penetrate the first carrier layer (11), and wherein the first fiber-reinforced carrier layer (11) is fluid-tight.
14. The structural panel (10) according to Claim 13, characterized in that the laminate structure has a second fiber-reinforced carrier layer (12) which is connected to a second side of the foam layer (13) opposite the first side, and wherein the grooves (21, 22, 23, 26) completely penetrate the second carrier layer (12).
15. The structural panel (10) according to Claim 13 or 14, characterized in that the groove pattern (20) has a honeycomb pattern (25).
16. The structural panel (10) according to any of Claims 13 to 15, characterized in that the groove pattern (20) has regions having a different local groove depth, a different local groove width, a different local groove profile, and/or a different local groove density.
17. The structural panel (10) according to any of Claims 13 to 16, characterized in that at least some of the grooves (21, 22, 23, 26) have a V-shaped, trapezoidal, or rectangular groove profile or a groove profile having two parallel groove walls.
18. The structural panel (10) according to any of Claims 13 to 17, characterized in that the foam of the foam layer (13) is closed-cell and/or is a rigid foam.
19. The structural panel (10) according to any of Claims 13 to 18, characterized in that the first carrier layer (11) and/or second carrier layer (12) has a fiber-reinforced plastics panel.

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